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The Government of Canada has published a comprehensive framework for the risk assessment of manufactured nanomaterials under the Canadian Environmental Protection Act, 1999 (CEPA). The framework was developed by Health Canada and Environment and Climate Change Canada, and was published in March 2026. It provides detailed guidance on how nanomaterials are assessed for potential risks to human health and the environment within the existing chemicals management system.

Adapting Existing Chemical Risk Frameworks to Nanoscale Materials

The framework confirms that nanomaterials are regulated under existing CEPA provisions, rather than through a separate regulatory regime. However, it emphasizes that traditional risk assessment approaches require adaptation to account for the unique physical and chemical properties of materials at the nanoscale. These include characteristics such as particle size (1–100 nm), shape, surface chemistry, and reactivity, which can significantly influence exposure, environmental fate, and toxicity compared to bulk substances.

Canada follows international approaches, including those developed by the OECD, by applying existing regulatory frameworks while introducing nanospecific considerations. This approach ensures consistency while addressing scientific uncertainties associated with emerging nanotechnologies.

Key Risk Assessment Considerations for Nanomaterials

The framework outlines several elements that distinguish the risk assessment of nanomaterials from the conventional evaluation of chemicals. These include the need to assess multiple nanoforms of the same substance, since different forms may exhibit different hazard profiles despite sharing the same chemical composition. The framework also highlights the importance of evaluating transformations throughout the lifecycle, including during production, use, and disposal, as nanomaterials may alter their form and behaviour depending on environmental conditions.

In addition, the framework introduces advanced methodologies such as grouping strategies, read-across approaches, and modelling tools to address data gaps. Given the limited availability of experimental data for many nanomaterials, these approaches are essential for supporting robust and efficient risk assessments.

Focus on Human Health and Environmental Exposure

A central component of the framework is the detailed assessment of exposure pathways and health effects. With regard to human health, particular emphasis is placed on inhalation exposure, as nanoparticles have the ability to penetrate deep into the respiratory system and potentially translocate within the body, making it a critical route. The framework also considers exposure through consumer products, food, water, and environmental media.

From an environmental perspective, the framework highlights the importance of understanding the fate and behaviour of nanomaterials, including their aggregation, dissolution, and interaction with natural systems. These factors influence how nanomaterials move through air, water, soil, and sediment, ultimately determining their ecological impact.

Application of Weight of Evidence and Precautionary Approach

Consistent with CEPA principles, the framework applies a weight-of-evidence (WoE) and precautionary approach to address uncertainties in data and scientific knowledge. This means that regulatory decisions are based on multiple lines of evidence, combined with conservative assumptions where necessary to protect human health and the environment.

The framework also acknowledges that not all nanomaterials pose increased risks, but emphasizes the need for case-by-case evaluation, given the variability in nanoscale properties and applications.

Supporting Innovation While Strengthening Chemical Safety Oversight

The publication of this framework reflects Canada’s recognition of the increasing use of nanotechnology across industries, including electronics, healthcare, materials science, and consumer products. By providing clear guidance on risk assessment methodologies, the government aims to support innovation while ensuring that potential risks are identified and managed effectively.

Overall, the framework promotes transparency in regulatory decision-making, reinforcing Canada’s science-based approach to chemical management and ensuring that emerging technologies, such as nanomaterials, are assessed with the necessary rigor to protect both human health and the environment.